python sort

    
    __author__ = 'shellbye'
    
    
    def sort_list():
        a = [3, 6, 8, 2, 78, 1, 23, 45, 9]
        # simple return the result and don't change a
        print sorted(a)
        print a
        # return None and changed a
        print a.sort()
        print a
    
        b = [3, 6, 8, 2, 78, 1, 23, 45, 9]
        print sorted(b, reverse=True)
        print b
    
        b.sort(reverse=True)
        print b
    
    
    def sort_tuple():
        tup = (3, 6, 8, 2, 78, 1, 23, 45, 9)
        # tuple cannot be changed so it does not have the sort method
        print sorted(tup)
    
    
    def sort_list_by_inside_list():
        # tuple is the same
        def get_first_key(item):
            return item[0]
    
        def get_second_key(item):
            return item[1]
    
        l = [[2, 3], [6, 7], [3, 34], [24, 64], [1, 43]]
        print sorted(l, key=get_first_key)
        print sorted(l, key=get_second_key)
    
    
    def sort_list_by_inside_list_with_lambda():
        # tuple is the same
        l = [[2, 3], [6, 7], [3, 34], [24, 64], [1, 43]]
        print sorted(l, key=lambda item: item[0])
        print sorted(l, key=lambda item: item[1])
    
    
    def sort_list_by_object():
        # http://www.pythoncentral.io/how-to-sort-a-list-tuple-or-object-with-sorted-in-python/
        class Custom(object):
            def __init__(self, name, number):
                self.name = name
                self.number = number
    
            def __repr__(self):
                return self.name + "--" + str(self.number)
    
        def get_key(custom):
            return custom.number
    
        custom_list = [
            Custom('object', 99),
            Custom('michael', 1),
            Custom('theodore the great', 59),
            Custom('life', 42)
        ]
        print sorted(custom_list, key=get_key)
    
    
    def sort_list_by_different_object():
        # http://www.pythoncentral.io/how-to-sort-a-list-tuple-or-object-with-sorted-in-python/
        class Custom(object):
            def __init__(self, name, number):
                self.name = name
                self.number = number
    
            def __repr__(self):
                return self.name + "--" + str(self.number)
    
            def __cmp__(self, other):
                if hasattr(other, 'get_key'):
                    return self.get_key().__cmp__(other.get_key())
    
            def get_key(self):
                return self.number
    
        class AnotherObject(object):
            def __init__(self, tag, age, rate):
                self.tag = tag
                self.age = age
                self.rate = rate
    
            def __repr__(self):
                return self.tag + "--" + str(self.age)
    
            def __cmp__(self, other):
                if hasattr(other, 'get_key'):
                    return self.get_key().__cmp__(other.get_key())
    
            def get_key(self):
                return self.age
    
        custom_list = [
            Custom('object', 99),
            Custom('michael', 1),
            Custom('theodore the great', 59),
            Custom('life', 42),
            AnotherObject('bananas', 37, 2.2),
            AnotherObject('pants', 73, 5.6),
            AnotherObject('lemur', 44, 9.2)
        ]
    
        print sorted(custom_list)
    
    
    def sort_list_by_inside_dict():
        dl = [
            {"name": "shellbye", "grade": 99},
            {"name": "jack", "grade": 98},
            {"name": "lee", "grade": 97},
        ]
    
        print sorted(dl, key=lambda u: u['grade'])
    
    
    def sort_dict_by_value():
        doc = {
            'key0': 98,
            'key1': 97,
            'key2': 5,
            'key3': 60,
            'key4': -9,
        }
        print doc.get
        sorted_doc = sorted(doc.items(), key=lambda t: t[1])
        print sorted_doc
    
    
    def sort_dict_by_value_advance():
        # http://stackoverflow.com/questions/575819/sorting-dictionary-keys-in-python
        # http://stackoverflow.com/questions/613183/sort-a-python-dictionary-by-value
        # http://stackoverflow.com/questions/9285930/methods-for-sorting-a-dictionary
        doc = {
            'key0': 98,
            'key1': 97,
            'key2': 5,
            'key3': 60,
            'key4': -9,
        }
        print doc
        sorted_doc = sorted(doc, key=doc.get)
        print sorted_doc
    
    
    def sort_dict_by_key():
        doc = {
            'key0': 98,
            'key1': 97,
            'key2': 5,
            'key3': 60,
            'key4': -9,
        }
        print doc
        sorted_doc = sorted(doc.keys())
        print sorted_doc
    
    
    if __name__ == "__main__":
        print "Let's sort!"
        # sort_list()
        # sort_tuple()
        # sort_list_by_inside_list()
        # sort_list_by_inside_list_with_lambda()
        # sort_list_by_object()
        # sort_list_by_different_object()
        # sort_list_by_inside_dict()
        # sort_dict_by_value()
        # sort_dict_by_value_advance()
        sort_dict_by_key()